On November 30, 2017, ESA signed two contracts today with Italy's ELV (European Launch Vehicle) and Thales Alenia Space to extend Europe's Vega space system capabilities and competitiveness, and develop Space Rider for a payload return capability. ELV S.p.A., the prime contractor of Vega development, is a company established by Avio and ASI (Italian Space Agency) in December 2000. 1)

ELV will develop and extensively test a new European cryogenic upper stage engine development model for Vega evolutions beyond 2025, based on low-cost liquid oxygen–methane propulsion.

The engine replaces the current Zefiro-9 solid-propellant motor and the AVUM upper stage engine for Vega-E, matching Vega-C performance at significantly reduced costs and improved flexibility.

In addition, complementing the SSMS (Small Spacecraft Mission Services) program already under development, ELV will investigate how existing motors such as the P120, P80, Z40, Z23, Z9, could be used to create a family of Vega-E configurations able to place payloads of 200–2500 kg into orbit. - This will incorporate promising technologies in the areas of 3D layer-by-layer additive manufacturing, hydrogen peroxide as low-toxicity propulsion, and advanced avionics, offering competitive production and operational costs.

The contract concerning the Vega evolution activities worth €53 million was signed by ESA Director of Space Transportation Daniel Neuenschwander and ELV Managing Director Andrea Preve at ESA headquarters in Paris. - In parallel, Thales Alenia Space and ELV will complete the detailed mission and system design up to the CDR (Critical Design Review) for Space Rider.

At the ESA Ministerial meeting in December 2014, Member States agreed to begin developing the more powerful Vega-C, now expected to debut mid-2019, with the main objectives:

• to strengthen Vega's position in the market in the short to medium term

• to increase launch vehicle performance by at least 300 kg and increase the flexibility for multiple payloads missions

• to be able to introduce the Vega-C configuration to the market from end-2018 at a cost no higher than today's Vega, profiting from the shared development with Ariane 6 of the first-stage motor

• to reduce the dependency on non-European sources in launcher production at no extra cost

• to respond better to long-term institutional needs

• to help maintain European industrial engineering capabilities, particularly in propulsion, in parallel to the Vega and Vega-C exploitation.

Additional improvements are being studied to enable Vega to carry micro- and nanosatellites in order to be cost-effective in this emerging market.

The Space Rider space transportation system will be integrated with Vega-C, combining an Orbital Service Module derived from a Vega-C AVUM (Attitude Vernier Upper Module) and a reentry module derived from the IXV (Intermediate eXperimental Vehicle) demonstrator flown in 2015 on Vega.

It will provide Europe with an affordable reusable platform for routine access and return from space, with payloads capacity up to 800 kg to an array of orbit altitudes and inclinations for multiple applications such as advanced microgravity, in-orbit demonstration and validation for Earth observation, science, telecommunication and robotic exploration.

Figure 2: Space Rider will provide Europe with an affordable reusable platform for routine access and return from space, with a payload capacity up to 800 kg to an array of orbit altitudes and inclinations for multiple applications such as advanced micro-gravity, in-orbit demonstration and validation for Earth observation, science, telecommunication and robotic exploration (image credit: ESA)

The Space Rider design builds on technological and industrial knowhow from Vega, Vega-C and the IXV development and demonstrations. The contract for Space Rider activities, worth €36.7 million, was signed by ESA Director of Space Transportation Daniel Neuenschwander, Thales Alenia Space Vice President Domain Exploration and Science Walter Cugno, and ELV Managing Director Andrea Preve at ESA headquarters in Paris.

The Vega and Space Rider development programs provide the framework to consolidate a Vega space system able to capture the broadest market needs with Vega-C and its spin-offs products: SSMS, Space Rider, and the VEnUS (Vega Electric Upper Stage), covering access to LEO (Low Earth Orbit) for payloads up to 2300 kg, orbital transfer from LEO, and return from LEO, for a multitude of space applications in a competitive manner.

Figure 3: Space Rider mission: Following on from the successful Vega–IXV mission in 2015, Space Rider will be launched from Europe's Spaceport in Kourou, French Guiana, reach and stay in orbit as long as required to perform the payload operations, deorbit and reenter performing a ground landing to return payloads to end users and be refurbished and reused for the next mission (image credit: ESA)

Vega-C

On the wave of Vega's success, Member States at the ESA Ministerial meeting in December 2014 agreed to develop the more powerful Vega-C to respond to an evolving market and to long-term institutional needs. Vega-C is expected to debut in mid-2019, increasing performance from Vega's current 1.5 ton to about 2.2 ton in a reference 700 km polar orbit, covering identified European institutional users' mission needs, with no increase in launch service and operating costs. 4)

The main objectives are to increase performances, reduce operating costs, provide cost-efficient launch services and reduce the dependency on non-European sources in launcher production at no extra cost.

Vega-C elements:

Vega-C is based on the existing Vega launcher and comprises four stages. Three stages will use solid-propellant motors and one will use liquid propellants.

The first stage is based on the P120C, the largest monolithic carbon fiber solid-propellant rocket motor ever built. Its development relies on new technologies derived from those of P80, Vega's current first stage motor and will provide a significant increase in performance. The P120C will also be used for the liftoff boosters on Ariane 6.

The second stage with the new Zefiro-40 (Z40) motor will contain about 36 tons of solid propellant providing an average thrust of 1100 kN.

The Zefiro-9 third stage, currently used on Vega, burns 10 tons of solid propellant.

The AVUM+ upper stage for orbital positioning and attitude control is derived from the current Vega AVUM but has a lighter structure. It carries more propellant inside larger tanks and features several new European-developed components. AVUM+ has a propellant mass of 0.74 tons and the main engine will provide an average thrust of 2.45 kN.

A larger fairing with an increased payload envelope (3 m in diameter) to accommodate larger satellites is also being developed. It will be suitable for Earth observation satellites of more than two tons, and the Space Rider reentry vehicle.

The total length of Vega-C is about 35 m with a mass at liftoff of 210 tons – a significant increase over the current Vega's 130 tons.

Vega-C will be launched from the same site used for Vega at Europe's Spaceport in Kourou, French Guiana.

Vega-C way forward:

ESA is overseeing the procurement and the architecture of the overall launch system, while industry is building the rocket with ELV S.p.A. as prime contractor. An industrial cooperation agreement has been signed between ASL (Airbus Safran Launchers) and Avio for the P120C solid motor.

The SDR (System Definition Review) of the Vega-C launch system has been completed and the development activities are proceeding as planned. The CDR (Critical Design Review) of the launch system is planned for the end of 2018, and the Ground Qualification Review in the first quarter of 2019.

The evolution requires modifications to the Vega launch pad and mobile gantry, such as a more powerful crane, new pallets, and modified fluid services. These modifications are being made in such a way to keep the pad and gantry compatible with both vehicles during the period when launches of Vega will be alternated with Vega-C.

The information compiled and edited in this article was provided by Herbert J. Kramer from his documentation of: "Observation of the Earth and Its Environment: Survey of Missions and Sensors" (Springer Verlag) as well as many other sources after the publication of the 4th edition in 2002. - Comments and corrections to this article are always welcome for further updates (herb.kramer@gmx.net).